Joanna Coles feels like she was obsessed with underwear while shooting Project Runway All Stars.

The reality television show sees 13 designers who have featured in previous series of the show but never won come back and attempt to be crowned the winner. Model Angela Lindvall is hosting in place of Heidi Klum, while designers Georgina Chapman and Isaac Mizrahi are judges.

Editor of US Marie Claire Joanna is taking over the reigns as mentor from Tim Gunn, a position she is terrified about. Tim is a firm fan favourite so rather than replacing him Joanna decided to try to find her own voice.

"We're very different, and I think having a female perspective helps. I found myself asking the designers, 'Why are you making an outfit that no one can wear underwear with?' Am I the only woman in America who wears underwear? I feel like my catchphrase in the workroom became, 'Well, what if she wants to wear underwear?'" she laughed to The Cut.

Joanna added she was able to be tougher on the designers as they are all more experienced of working in the industry now.

She did form a strong bond with several of the participants though, which made it hard when they made mistakes.

"Some of them just got in their own way, and you just wanted to say, 'What the hell are you doing?' And a couple of times I did. It's amazing how people can want something really badly, and the only obstacle is themselves," she mused.

Joanna went on to discuss her day job. She loves working for Marie Claire and opened up about the readers of the publication.

She sees them as diverse, which is why her front cover stars often vary so much. The editor is adamant Marie Claire readers will be amazed by Kim Kardashian's money making ability, but also by Angelina Jolie's career and home life.

However, she isn't so sure they would like to read about Britain's Duchess of Cambridge.

"I think it would be perverse of me to say no, because it would be an event cover," she replied, when asked if she'd feature Catherine Middleton on the cover. "But I don't think our reader is actually that interested in her. We actually didn't do anything on the royal wedding. You can get that stuff elsewhere. Were we able to do an exclusive cover with her, yes, of course we'd do it. And then it'd become an event."